Folding die guide means



1969 M. J. BERNING 3,459,014

FOLDING DIE GUIDE MEANS Filed March 18, 1968 i" a sa a 17 2g lNVENTOR/S 27 MELV/NJ. BERN/N6,

'- 1e 1 BY "United States Patent C) i 3,459,014 FOLDING DIE GUIDE MEANS Melvin .l. Berning, Cincinnati, Ohio, assignor to The Louis G. Freeman Company, Cincinnati, Ohio, a corporation of Ohio Filed Mar. 18, 1968, Ser. No. 713,789 Int. Cl. C14b 1/00 US. Cl. 69-1 7 Claims ABSTRACT OF THE DISCLOSURE Guide means for insuring the sequential folding of the adjacent edges of a workpiece, the guide means being in the form of resilient fingers which are adapted to engage and initiate the infolding of selected edges of the workpiece in advance of the adjoining edges of the workpiece.

Background of the invention This invention relates to folding dies of the type disclosed in US. Patent No. 3,073,141 which are primarily intended for use in the shoe industry for forming decorative leather articles, such as bows, discs, simulated buckles and the like. Such articles are usually formed from a preshaped piece of sheet material, such as leather, the marginal edges of the piece being doubled back and adhered to form a finished edge.

In accordance with the teachings of the aforementioned patent, the folding operation is performed by coacting upper and lower die assemblies which are reciprocated relative to each other. The lower die assembly includes a die cavity configured to conform to the contour of the folded article, there being a sliding plate overlying the die cavity having an aperture therein adapted to be aligned with the cavity, the aperture being surrounded by a recessed shoulder on which the unfolded article is seated and aligned with the die cavity. The upper die assembly mounts a depending folding element of slightly lesser dimensions than the die cavity and movable into the die cavity to press the workpiece downwardly therein, such movement causing the marginal edges of the article to fold upwardly against the sides of the die cavity. Upon removal of the folding element from the die cavity, the sliding plate is shifted to a second position in which a shallow folding cavity formed in the undersurface of the sliding plate is juxtaposed to the upper end of the die cavity. The shallow folding cavity has inwardly curved edges which coincide with the edges of the die cavity. Thereafter, a resiliently mounted pressure block underlying the article in the die cavity displaces the article upwardly so that the upwardly projecting edges of the article enter the shallow folding cavity and are simultaneously infolded by its inwardly curved edges. The folded article is thus compressed into the folding cavity, whereupon the sliding plate is shifted to remove the article from the area of the die cavity, whereupon the folded article may be removed from the folding cavity.

While die assemblies of the character described have been successfully used to fold diverse types of articles, a problem has been encountered at the corners of the articles if it is desired to fold the adjoining edges neatly and evenly one over the other. Usually the ends are cut at angles such that the edges do not overlap when infolded, but where an overlap is required there has hitherto been no way of producing it since the dies would simply bunch the material together at the corners.

The instant invention overcomes the foregoing difficulty by providing resilient fingers which coact with the folding cavity to sequentially infold selected edges of the article being folded.

3,459,014 Patented Aug. 5, 1969 Summary of the invention The instant invention contemplates the provision of a sliding plate having a shallow folding cavity provided with flexible fingers, preferably in the form of spring steel wires, which project inwardly from the curved edges of the folding cavity so as to engage and initiate infolding movement of the edges of the article contacted thereby in advance of the infolding movement of the adjoining edges of the article, the infolding of which is accomplished by the curved edges of the folding cavity. The spring fingers are themselves deflected as the pressure block presses the article into the folding cavity, the fingers retracting into underlying slots in the sliding plate, so that the final infolding and compression of the folded edges of the workpiece is accomplished by coaction between the pressure block and the folding cavity, the fingers having been effectively retracted and hence removed as an obstacle to the pressing together of the folded edges.

Brief description of the drawings FIGURE 1 is a vertical sectional view showing the upper and lower die assemblies in open condition with the sliding plate positioned to align an unfolded article for folding.

FIGURE 2 is a vertical sectional view similar to FIG- URE 1 but showing the upper and lower die assemblies in mating engagement with the edges of the article folded upwardly by the coaction of the upper and lower dies.

FIGURE 3 is a vertical sectional view showing the sliding plate in its alternate position of use with the folding cavity overlying the die cavity.

FIGURE 4 is a bottom plan view of the sliding plate which incorporates resilient folding fingers in accordance with the instant invention.

FIGURE 5 is an enlarged fragmentary sectional view taken along the line 5-5 of FIGURE 4.

FIGURE 6 is a fragmentary plan view of an article having its edges folded in accordance with the invention.

Description of the preferred embodiments The die assemblies illustrated, which are of the type disclosed in the aforementioned US. Patent No. 3,073,- 141, are adapted to be mounted in a conventional cut-out machine of the type widely employed in shoe manufacturing plants to perform a variety of operations. Machines of this character are provided with a vertically reciprocating upper platen to which the upper die assembly is secured, and a fixed lower base platen or anvil to which the lower die assembly is secured. In such machines the upper platen member may be reciprocated either in a slow gentle stroke or in a rapid power stroke depending upon the particular operation being performed.

The upper die assembly comprises a base plate 10 mounting a male die 11 configured to conform to the body of the decorative article being acted upon. The base plate 10 will be secured to the reciprocating upper platen of the cut-out machine by means of mounting lugs 12, and on its undersurface it is provided with a set of depending stripping pins 13 which act to remove the folded articles from the folding cavity forming a part of the sliding plate.

The lower die element comprises a base plate 14 adapted to be supported on the lower platen or anvil of the machine, the base plate mounting a die block 15 supported by a plurality of vertically movable guide pins 16 surrounded by spring 17 extending between the base plate 14 and the die block 15, the springs normally serving to bias the die block to its uppermost position, which is illustrated in FIGURE 1. The die block mounts a horizontally movable sliding plate 18 provided with a forwardly projecting handle 19 by means of which the sliding plate may be moved back and forth relative to the die block from a forward to a rearward position.

As best seen in FIGURE 4, the sliding plate is provided with a configured orifice through which the male die 11 is adapted to pass, the orifice 20 being surrounded by a recessed shoulder 21 which supports the marginal edges of the ornamental article to be folded. The shoulder 21 thus serves as a means for positioning the ornamental article in alignment with the die element.

The ornamental article is illustrated at 22 in FIG- URE 6, the extending marginal edge portions 23 being shown in the unfolded condition in the left portion of the figure. It will be understood that in the unfolded condition the marginal edges 23 will be supported by the recessed shoulder 21 of the sliding plate.

The sliding plate 18 has a forward or loading position in which it projects forwardly toward the machine operator. This position is illustrated in FIGURE 3, and it will be understood that when the sliding plate is in its forward or loading position, the operator will place an unfolded article 22 in the recess defined by the shoulder 21, whereupon the sliding plate 18 will be shoved rearwardly to its operating position in which the article is in vertical alignment with the male die element 11.

A female die cavity 24 is formed in the die block 15 in vertical alignment with the male die element 11, the cavity 24 extending through the die block and normally being closed by a pressure block 25 mounted on a pressure plate 26 overlying the base plate 14, the pressure plate and block being biased upwardly by means of springs 27 as seen in FIGURE 1. The pressure block 25 normally lies within the female die cavity 24 but is movable downwardly by the male die 11 as it enters the female die cavity.

When the operator actuates the machine to reciprocate the upper die assembly, the male die element 11 will move downwardly through the orifice 20, carrying the article 22 with it, the marginal edges 23 of the article being turned upwardly about the sides of the male die element, the parts thus assuming the position illustrated in FIGURE 2, wherein it will be seen that the marginal edges 23 are maintained in an upwardly turned position by the wall surfaces of the female die cavity 24. At the same time, the downward movement of the male die element 11 moves the pressure block 25 and plate 26 downwardly, the plate 26, when the upper die element reaches its lowermost position, being juxtaposed to the upper surface of base plate 14. As the plate 26 moves downwardly it contacts the spring biased locking elements 28 which are cammed outwardly by the plate but which, when the plate seats against the base plate 14, spring inwardly to secure the pressure plate and block in their lowermost positions so that, as the male die element travels upwardly on its return stroke, the article 22 will remain in the female die cavity seated against the upper surface of the block 25, as seen in FIGURE 3. Preferably, the upper die assembly will be reciprocated slowly as the male die element 11 carries the article into the die cavity 24 and depresses pressure block 25 and plate 26.

When the male die element 11 has returned to its uppermost position, the operator slides the plate 18 forwardly to its forward or loading position so that another blank may be positioned in the recess defined by the shoulder 21. However, as will be evident from FIG- URE 3, when the sliding plate 18 is moved to its forward position, a configured folding cavity 29 formed in the undersurace of plate 18 will be brought into vertical alignment with the female die cavity 24. As will be seen in FIGURE 4, the folding cavity 29 is configured to conform to the body of the ornamental article 22, the folding cavity having curved edges 30 which, as will be explained more fully hereinafter, act to infold the marginal edges 23 of the article.

When the sliding plate is in the forward position illustrated in FIGURE 3, the machine operator again actuates the machine to move the upper die assembly downwardly, preferably with a sharp power stroke, thus causing the male die element to strike the upper surface of sliding plate 18 and move both the sliding plate and the underlying die block 15 downwardly against the compression of springs 17. This movement acts to displace the die block 15 and the female die cavity 24 therein downwardly about the pressure block 25, thereby causing the article 22 to be pushed upwardly into the folding cavity 29. As the die block 15 moves downwardly, it exerts a camming action against the locking elements '31, causing them to move outwardly, thereby releasing the pressure plate 26 for upward movement and permitting the pressure block 25 and plate 26 to return to the position illustrated in FIGURE 1.

Normally, when the article 22 is pushed upwardly into the folding cavity 29, the rounded edges 30 of the folding cavity cause the upwardly projecting marginal areas 23 of the article to be folded inwardly and pressed into contact with the underlying portions of the article. However, as previously indicated, the curved walls of the folding cavity act simultaneously on all marginal edge portions of the article, and hence if adjoining marginal edge portions 23 meet at a corner, the edges tend to bunch rather than fold evenly one upon the other. In the particular decorative article illustrated, such bunching problem was encountered at the corners 31 and 32 of the folding cavity, as indicated in FIGURE 4.

In accordance with the instant invention, the bunching problem is eliminated by providing resilient fingers 33 which project inwardly into the folding cavity 29 adjacent the corners 31 and 32. As seen in FIGURE 5, each of the fingers 33 may comprise an elongated piece of spring wire having a free end 34 projecting inwardly into the folding cavity 29 so as to overlie the curved wall portion 30 of the folding cavity. The spring wire is received in a slot or recess 35 in the undersurface of the sliding plate and has its opposite end 36, which is preferably in the form of a loop, secured to the plate by means of countersunk set screw 37.

The recess 35 has a forward extension 38 which underlies the curved wall portion 30 of the folding cavity in alignment with the free end 34 of the finger, the end 34 of the finger being deflectable into the recessed portion 38 when the pressure pad 25 forces the article into the folding cavity. However, during initial movement of the article 22, the upturned edges 23 underlying the ends 34 of the fingers first contact the fingers with the result that infolding of the marginal edges 23 of the article is initiated by the fingers in the manner illustrated in dotted lines in FIGURE 5, which occurs prior to the infolding of the remaining marginal edges of the article which are not under the influence of the fingers, the folding of the latter areas being accomplished as they contact the curved wall portions 30 of the folding cavity. Thus, with joint references to FIGURES 4 and 6, the marginal edge portion 23a of the workpiece, which contact the ends of the fingers 33, are infolded first i.e., in advance of contact with the adjacent curved wall portions 30a of the folding cavity, whereas the adjoining marginal edge portion 23b is infolded by the curved wall portion 30b of the die cavity and hence has its end edges overlying the end edges of marginal portions 23a, thereby providing neatly folded corners. Of course, as the folded article is tightly pressed into the folding cavity 29 by the action of pressure block 25, the free ends 34 of the fingers will be deflected into the underlying portions 38 of the recesses and the folded edges of the article flattened into contact with the underlying portions of the article.

The resilient fingers thus serve as a simple yet highly effective means for guiding the marginal edges of the article being folded and insure the formation of neat overlapping corners. While a preference has been expressed for guide fingers formed from spring wire, it will be understood that the fingers may be formed from any material which is sufficiently rigid to initiate infolding of the marginal portions of the article contacted thereby and yet sufficiently resilient to be deflected into the underlying finger receiving recesses when a folded workpiece is fully inserted in the folding cavity.

It will be understood also that the number and position of the fingers does not constitute a limitation on the invention, the number and location of the fingers being determined by the contour of the article being folded and the presence of abutting edges which might cause undesirable bunching.

After the folded article has been pressed into the cavity 29 and the upper die assembly retracted to its elevated position, the sliding plate will be moved to its rearward position, whereupon on the next succeeding downward stroke 'of the upper die assembly, the stripping pins 13 carried by the upper die assembly will be caused to pass through pin receiving openings 39 overlying the folding cavity 29, in the manner illustrated in FIGURE 2, thereby causing the folded article to be stripped from the folding cavity.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A sliding plate for use in a folding die having a die cavity underlying the plate, a folding cavity in the undersurface of said plate adapted to 'be aligned with the cavity in the folding die, said folding cavity having curved edges extending inwardly from the outermost edges thereof, said folding cavity having a corner therein, a guide finger extending inwardly into said folding cavity from an outer edge thereof and lying in spaced relation to a curved edge of said folding cavity, said finger being positioned adjacent said corner at substantially right angles to an edge of said cavity defining one edge of said corner and means resiliently maintaining said finger in spaced relation to the said curved edge of the folding cavity.

2. The sliding plate claimed in claim 1 wherein a recess underlies said finger, and wherein said finger is displaceable into said recess.

3. The sliding plate claimed in claim 2 wherein the dimensions of said recess are such that said finger may be wholly contained therein at least in the area of said folding cavity.

4. The sliding plate claimed in claim 3 wherein said finger comprises a length of spring wire.

5. In a folding die having a die cavity into which a piece of leather or the like is inserted and its marginal edges folded upwardly, there being a sliding plate overlying said die cavity and movable between a forward and a rearward position, an orifice in the folding plate adapted to overlie the die cavity when the plate is in its rearward position, and a folding cavity in the undersurface of the plate adapted to overlie the die cavity when the plate is in its forward position, said folding cavity having a corner therein, the folding cavity having curved edges extending inwardly from the outermost edges thereof for infolding the marginal edges of the article when the article. is pushed upwardly from the die cavity into the folding cavity, the improvement which comprises a resilient finger extending inwardly from an outer edge of said folding cavity, said finger being positioned adjacent said corner at substantially right angles to an edge of said cavity defining one edge of said corner said resilient finger overlying a curved edge of said folding cavity in spaced relation thereto so as to initiate the infolding of the upturned marginal edge of the article upon contact with said finger in advance of the infolding of adjoining marginal edge portions of the article by the said curved edges of the folding cavity.

6. The folding die claimed in claim 5 wherein a slot of the size to receive said finger is formed in said folding cavity underlying said finger, said finger being displaceable into said recess.

7. The folding die claimed in claim 6 wherein said finger comprises a length of spring wire having one end extending into said folding cavity and its opposite end fixedly secured to said folding plate beyond the outermost edge of said folding cavity.

References Cited UNITED STATES PATENTS 2,394,219 2/1946 Vachon 93-51 X 2,453,623 11/1948 Gilbert et al. 12-55 X 2,503,589 4/1950 Noecker 12-55 X 3,073,141 l/1963 Freeman 69-1 3,382,687 5/1968 Freeman 691 ALFRED R. GUEST, Primary Examiner 

